Pharmacists hold a vastly underrecognized role within the care team—a role that offers a unique approach toward the therapeutic management of rare diseases.
On February 28, 2022, 106 countries will come together for Rare Disease Day. This global event has been observed since 2008 to increase awareness and advocate for those impacted by rare diseases.
Nationwide, rare diseases affect an estimated 30 million individuals, but what quite defines a disease as being rare? Unfortunately, it’s not a straightforward answer. Per the 1984 amendment to the Orphan Drug Act of 1983 (ODA), the United States classifies a disease as being rare when less than 200,000 people are affected.1,2
Today, more than 7000 diseases fit this definition, ranging from more well-known conditions such as multiple sclerosis and cystic fibrosis, to diseases most people have never heard of, such as Prader-Willi syndrome and Friedreich’s ataxia.3 Patients with rare conditions have highly complex treatment needs, requiring a multi-disciplinary care team approach.
Pharmacists hold a vastly underrecognized role within this team—a role that offers a unique approach toward the therapeutic management of rare diseases.
The development and designation of orphan drugs has tremendously improved since the passage of the ODA, but progress is still to be made. The orphan drug market is expected to surpass $217 billion in sales by 2024, which is a staggering cost despite their utility in rare conditions. Today, only approximately 10% of rare diseases have FDA-approved therapies.4
As a consequence, the remaining 90% of patients with a rare disease are left without standard treatment options and often have to rely on off-label drug use or no treatment at all. Although off-label prescribing of medications is not generally a preferred approach, it does play a pertinent role in rare conditions.5
When faced with this situation, pharmacists must consult drug information resources, primary literature, and use their clinical knowledge to best assist prescribers. Thus, it’s important that pharmacists remain up to date on new drug approvals, drug safety warnings, and medical literature to properly partake in the care of rare disease patients.
Examples of rare diseases that currently require this approach include Alpers-Huttenlocher syndrome (AHS), aromatic L-amino acid decarboxylase (AADC) deficiency, and Rett syndrome.6,7 AHS, is a neurological disease characterized by seizures, hepatic insufficiency, and cognitive decline.
For seizure management in this population, it is well-documented that valproic acid should be avoided due to its hepatoxic effects accelerating the progress to liver failure. Pharmacists can recommend antiepileptics that are less reliant on hepatic metabolism, such as levetiracetam, topiramate, and lacosamide.7,8
AADC deficiency is a genetic neurometabolic disorder that results in the improper synthesis of vital neurotransmitters—namely, serotonin, and dopamine. Because of the nature of this disease, pharmacists can offer guidance on medications to avoid. Limited reports exist, but central dopamine antagonists and serotonergic antagonists should be avoided because they can worsen symptoms.9
A pharmacist can apply the same principle to Rett syndrome and other rare conditions, overall improving patient outcomes and enhancing the knowledge of the care team. Pharmacists serve as the final barrier between a patient and their medications and are the last step in the medication use process.
Therefore, it’s important they remain up to date on new drug approvals, drug safety warnings, and medical literature to properly partake in the care of patients with a rare disease.
Orphan drugs that do gain FDA-approval also come with their own set of challenges. The FDA’s approval process of orphan drugs is rather complex.
In short, once a drug receives official designation as an orphan drug, its approval has the potential eligibility to undergo 1 of the FDA’s 4 expedited programs: Breakthrough Therapy, Priority Review, Fast Track, or Accelerated Approval. FDA-approved novel orphan drugs often result from clinical trials with small study populations.1,10
Per the nature of the disorders that orphan drugs intend to treat, this is no surprise. In addition, the familiarity of rare diseases and their available treatments typically isn’t common knowledge—it requires experience.
In addition to monitoring for adverse reactions, and drug interactions, pharmacists can address patient-specific barriers. For instance, swallowing difficulties can majorly impact medication adherence.
Dysphagia can be due to age extremes, manifestations of the disease itself, or medications. Pharmacists can recommend appropriate strategies to aid rare disease patients in overcoming this barrier.
Rare conditions that include dysphagia in its clinical presentation include myasthenia gravis, eosinophilic esophagitis, and amyotrophic lateral sclerosis (ALS).11 Examples of orphan drugs that come in oral solution formulations include riluzole (Tiglutik) for ALS; nimodipine (Nymalize) for ischemic deficits in subarachnoid hemorrhage; and calcium, magnesium, potassium, and sodium oxybates (Xywav) for type I and type II narcolepsy in patients 7 years of age and older.12-14
An additional barrier faced by patients with a rare disease is access to disease-specific care; however, 2 years ago, progression toward overcoming this barrier began. In 2020, URAC announced its new opportunity for specialty pharmacies to obtain the “Rare Disease Pharmacy Center of Excellence Designation.”
This special distinction solidifies the role that a pharmacist can have in the realm of rare disease, extending the definition of a specialty pharmacy to include patients with highly unmet needs. Currently, 8 states have this designation. Although still few in number, the presence of rare disease pharmacies as a whole is essential in improving care to the rare disease population.15
Rare Disease Day allows individuals across the globe to reflect on how far we’ve come, and yet, how far we still must go to adequately serve this population. Each patient afflicted by a rare disease has a unique story—a story that led to a journey they never thought they would be a part of.
The dynamic role of the pharmacist in rare disease care is vital to recognize. As steadfast advocates for their patients, pharmacists are able to provide highly personable care that can be just as impactful as pharmacotherapy.